Boiler-tube cleaner.



PATENTED MAY 28, 1907.

A. STEWART. BOILER FLUE CLEANER. APPLICATION FILED SEPT. 26, 1906.

3 vwantoz Wit" eases UNITED STATES PATENT oFFIoE.

ARCI-IIBALD STEWART, OF KEOTA, IOWA.

BOlLER-FLUE CLEANER- Specification of Letters Patent.

Patented May 28, 1907.

Application filed September 26, 1906. Serial No. 336,244.

whereby a small area of the flue being cleaned 1s expanded at a time sothat the scale cracks and drops therefrom after which the area thusheated and treated is immediately cooled and restored to its normalcondition.

With the foregoing object in view my invention consists in certain novelmechanism and procedure which will be hereinafter more fully describedand pointed out in the claims.

In the accompanying drawings: Figure 1 is a view partly in sectionthrough a water tube boiler and showing portions of the cleaningapparatus in elevation. Fig. 2 is an enlarged sectional view showing thenozzles in position within a tube.

A, represents a boiler having tubes a, b, c, and (1 shown inlongitudinal section therein, B, is a tank containing burning fluid, eis a pipe of suflicient length to reach to the inner end of the boilertubes and carrying on its inner end a perforated burner nozzle g whichis centered in the middle of the boiler flue by the centering lugs (1shown in Fig. 2, which lugs as the term implies hold the nozzles in acentral position and so away from the. wall of the flue being treated. Aflexible hose 6 connects the pipe 6 with the tank B and a cock icontrols the discharge of burning fluid through the pipe e and burner g.An air blast pipe f supplies air to the flue being cleaned and thepurpose of this air inlet is to aid combustion and also to immediatelycool the portion of the pipe j ustcleaned. The letter a illustrates atubewhich has been cleaned, b a tube partly cleaned, and c and (1 tubesstill incrusted with the scale In the operation of my Improved apparatusand method, the cock 'b 1s opened and the burner lighted and theoperator inserts it in the outer end of the flue. As soon as gas-Patent, is

' two subscribing begins to escape from the burner and it is ig nited,the air blast is turned on through pipe tense heat 'on the inside oftheflue which at f with any desired force. This causes an monce expands atthe point being treated and the scale'at the same instant cracks andfalls off, whereupon the burner is pushed along through the flue and theprocess is continued, until the flue has beeIi' heated and cleanedthroughout its entire length. The fierce air blast that follows up theburner and creates the intense heat, also cools off the cleaned part ofthe flue and thus longitudinal expansion of the flue is reduced to aminimum, and in fact there is not sufficient expansion to injure theboiler. By this process it is never necessary cient heat iscreated andapplied to cause a local expansion and cracking of the incrustationwhich heating process is immediately followed by a cooling process, theair utilized thus performing the double function of aiding andsupporting combustion, and of cooling the heated. area. After a flue hasbeen cleaned the pipe 6 and burner g are removed and placed in another,and so the process is repeated until all are cleaned.

It is evident that. more or less sligh changes might be resorted to inthe form and arrangement of the several parts described withoutdeparting from the spirit and scope of my invention, and hence I do notwish to limit myself to the exact construction hereinv set forth, but

Having fully described my invention, what I claim as new and desire tosecure by Letters l. An apparatus for cleaning boiler flues consistingof a pipe having a burner thereon, and means for supplying air under"pressure and discharging it in rear ofthe burner.

2. An apparatus for cleaning boiler flues consisting of a pipe having aburner thereon, a "tank containing burning fluid, and a flexlbleconnection extending therefrom to the .pipe and means forsupplying airunder pressure and discharging it in rear of the burner.

testimony whereof I have signed my name to this specification in thepresence 0 witnesses. ROHIBALD STEWART.

Witnesses: a

A. S. FOLGER, EDMUND D.Monnrso1v.

. 7 to heat the flue to a red heat and just sufli-

